Tool for applying binding strap to railroad sleepers



Oct. 23, 1951 G. c. DELOR 2,572,323

. TOOL FOR APPLYING BINDING STRAPS I TO RAILROAD SLEEPERS Filed Jan, 12, 1946 2 SHEETSSHEET 1 Oct. 23, 1951 G. C. DELOR TOOL FOR APPLYING BINDING STRAPS TO RAILROAD SLEEPERS Filed Jan. 12, 1946 2 SHEETS-SHEET 2 MW/V/f/W/ Patented Oct. 23, 1951 TOOL FOR APPLYING BINDING STRAP TO RAILROAD SLEEPERS Gaston Charles Delor, Paris, France, assignor of one-half to Societe Nationale des Chemins de Fer Francais, Paris, France, a corporation of the French Republic; Frederic Edouard Marie Strahm administrator of said Gaston Charles Delor, deceased Application January 12, 1946, Serial No. 640,976

In France July 4, 1942 Section 1, Public Law 690, August s, 1946 Patent expires July 4, 1962 2'Claims. (Cl. 819.1)

Ithas already been. proposed to insure .the

shrinking of railroad sleepers and other wooden elements by means of a metal strip or strap surrounding the end of the sleeper which hasbeen previously compressed and held by means of a press so as to close the cracks therein; the strap is secured to this end inside a clasp and fastened after the manner of a bolt by means of special tool or pincers which allows its being folded over the clasp.

These special pincers includemeans for taking up slack in the strap, comprising self-adjusting jaws connected with the end of a traction screw adapted to move axially by rotation of a screw. The reaction exerted by the nut in the axial direction of the screw is applied to the sleeper to. be shrunk by means of a supporting part against which the lower ends of the pincers frame are adapted to bear.

The present invention has for its object improvements in pincers of this known type. characterized chiefly by the following points.

(at) These pincers are designed in a manner such that the strap may be submitted to no extension while it is being folded over the clasp.

(b) The bearing and guiding surfaces of the lower ends of the frame of the pincers are reduced to trunnions brought as near as possible to the underside of the supporting part applied against the sleeper so as to reduce the friction and the stresses involved in folding the strap; these bearing and guiding surfaces are on the outside of the flanges of this supporting part so as to free the portions nearest the fastening clasp and the strap.

The tensional screw of the tool is hollow so as to allow the passage through it of the end of the strap on which the self-adjusting mechanism connected with the screw exerts a tractional stress, said arrangement affording means for the shrinkage of a sleeper with a strap the length of which is as great as possible .and is not exactly predetermined as a function of the perimeter of the sleeper; the excess length may moreover be cut off after being folded over and the waste is used for forming the clamps holding the folded over end of the strap.

Appended drawings show solely by way of example a form of pincers improved in accordance with the present invention.

Fig. 1 is an elevational view of the pincers.

Fig. 2 is a cross-sectional view taken on the line IIII of Figs. 3 and 4.

Fig. 3 is a cross-sectional view taken on the line IIIIII of Figs. 2 and 4, but showing some parts in elevation.

Fig. 4 is a cross-sectional view taken on the line IV-IV of Fig. 2.

Fig. 5 is a diagrammatic view showing on a larger scale the pincers as they bear against the trunnion of the stationary part, and illustrating the steps taken during the folding over of the end of the strap.

Fig. 6 is a perspective view of the end of the strap after it has been positioned, folded over and clamped.

The strap is laid in the usual known manner over the sleeper while the latter is submitted to the action of a press which holds the cracks closed. This strap is constituted by a fiat iron or steel strip I the thickness of which varies with the value of the stresses involved in keeping the sleeper cracks closed. This thickness may vary between 3 and 6 millimeters and its width may vary between 16 and 25 millimeters.

The strap I is cut to the desired length. Owing to the improvements provided by this invention, this length does not require an accurate measurement as was the case in the prior systems. Such a requirement led heretofore to a considerable loss of time with, reference to the total average time for a shrinking operation.

One of the ends ofthe strap 1 (Fig. 6) is engaged inside the joining'clasp 2 and folded over with a hammer: into the shape shown, the folded over tongue la being inserted between the main body of the strap and the adjacent surface of the sleeper to be shrunk. The body of the strapped iron is shaped by a hammer and brought to bear against the periphery of the sleeper while the free end lb of the strap en gages the clasp 2. Before submitting this strap end lb to the tensional stresses exerted by the pincers, we insert the clamp 3. In accordance with one of the features of the present invention, this clamp (Fig. 6) is made with waste cut-off portions of the strap. It is engaged underneath the flat iron I in its open position shown in dot and dash lines in Fig. 6 and there is then fitted over the end la of the strap, the supporting part 4 by means of which the pincers bear against the upper surface of the sleeper.

In the form of execution designed in accordance with this invention, said part 4, which is seated upon the sleeper and overlies the clasp bar and the ends of the strap, includes two projections forming trunnions 5 of reduced diameter located as near as possible to the upper surface of the sleeper. These trunnions 5 may be provided for instance on the outer surfaces of two flanges 4a forming the part 4, said flanges 4a being interconnected by the s-tubshafts 6 riveted at their ends over said flanges and provided with central spacing bosses l fitting between the latter. The inner surfaces of the flanges 4a are shaped as illustrated so as to provide a recess 8 for housing snugly the joining clasp 2.

The two flanges 40 forming the part 4 being laid over the clasp 2, the position of said part 4 is well determined with referenceto the clasp and to the upper surface of the sleeper over which it bears. The trunnions 5 are consequently located with reference to said clasp in a perfectly accurate manner.

The tensioning pincers for the strap comprise, as well known, a tractional screw 80, provided with a square thread, engaging the tapped bore of a corresponding nut 9 forming the hub of the tap wrench ID or else adapted to be operated by a suitable control lever. In accordance with the invention, this screw 8a is hollow so as to allow its being engaged under conditions to be disclosed hereinafter by the end lb of the strap. The axial reactions exerted by the nut on the pincers are transmitted to the head ll of the latter through a thrust ball bearing i2. Said head II is connected through two uprights l3, constituted in the example shown, by structural members, to a lower bridge-shaped part I l. The connection between the uprights l3 and the head ll on one hand and the bridge-shaped part M on the other is made by screws l5 which allow 1 a dismantling as may be required for eventual repairs.

Between the bridge-shaped part l4 and the lower end of the screw 8a is inserted the automatic fastening device which takes hold of the I free end lb of the strap. This device includes two jaws l6 pivotally secured to axes ll which form spacing means between two flanges l8, said flange system being guided between the uprights l3. links l9 with a head secured as by welding to the lower end of the screw 8a.

The bridge piece [4 comprises two flanges 2| which have a downwardly tapering shape so as to present a general triangular appearance, said flanges being provided at their lower end with arcuate bearing surfaces 22 bearing against the corresponding trunnions 5 on the supporting part 4. When the bearing surfaces 22 are in engagement with said trunnions 5, the inner surfaces of the flanges 2l are in contact with the outer corresponding surfaces of the flanges 4a of part 4 with reference to which the pincers system is thus held transversely.

The working of the pincers is as follows:

Part 4 being set over the clasp 2 as explained hereinabove, and the pincers being held in the position indicated by the dot-and-dash line X (Fig. 2), the free end lb of the strap is inserted inside the slot 28 passing through the bridgepiece l4 and between the jaws l6 and into the axial bore of the hollow screw 8a. The operative surfaces of the jaws [6 are eccentrically shaped with reference to the axes l1. while the end lb of the strap is engaged between said jaws and consequently the rising motion of the head 28 under the action of the nut 9 will produce first a pivoting motion of the jaws by The jaws l6 are connected through short wedging them against the strap end lb and then points with a hammer so as to conform it to the shape of the sleeper and to cut it into the corners and edges thereof. During this ten-- sional movement to which the strap is submitted, the surfaces 22 bear against the trunnions 5 and the reactions cause the part 4 to bear against the upper surface of the sleeper into the wood of which it is thus strongly anchored without its relative position with reference to the clasp 2 being capable of modification.

When the tensional stress applied to the strap has reached a suitable value, the pincers system is rotated in the direction of the arrow (Figs. 2 and 5). During this movement, the metal of the strap is wound over the arm 2a of the clasp 2. In conformity with the invention this winding is performed under conditions such that the length L of the strap end lb between its point of tangency T with the transversal bar 2a 'of the clasp 2 and the point A at which it is seized between the jaws It remains constant during its deformation, i. e. the straight line T1A retains the same length as the inherent 'incurve'd lines TiA', TiA", TIAHI. This result is achieved by determining in a suitable manner the position and shape of the trunnions 5 against which the bearin surfaces 22 bear during the folding over movement.

The position and the shape of these trunnions depends in particular on the relative position of the clasp 2 and of the supporting part 4, as determined by the fitting of the clasp 2 inside the recess 8 of the part 4, said fitting being the same Whatever may be the depth at which said part 4 may engage the Wood of the sleeper under the forces to which it is submitted.

It will be observed from Fig. 5 that the trunnions 5 do not have perfectly cylindrical bearing surfaces engageable by the surfaces '22. The curved line AA'A' A' described by a point on the strap end lb as it is rotated by the pincers 3 under a constant tension, is similar to the trunnion bearing surfaces. The shape of the trunnion bearing surfaces may be determined by inscribing a curved line, such as AA'--AA", about the clasp bar 2a by a strap held undera constant tension.

When the rotating movement of the pincers is at an end, the pincers are removed and the excess length of the hat iron may be removed by any suitable means, such as a chisel. The waste is used for one or more clamps 3 adapted for use in a subsequent shrinking operation. The folding over of the terminal element lb being brought to a finish with a hammer, the raised flap 3a of the clamp 3 already half fitted over it as explained hereinabove is folded over as illustrated in full lines in Fig. 6. The shrinking operation is thus finished.

In conformity with a modification of our invention, the trunnions 5 may be provided on the clasp; the part 4 being omitted. This modification which is advantageous through its simplicity is of interest for shrinking-wooden parts.

What I claim is:

1. A tool for tensioning a strap around an article and folding over the free end of the strap about a clasp bar arranged transversely of the strap, which tool comprises a base portion having a recess opening downwardly in the bottom thereof, said base including upstanding flanges which are secured together in spaced relationship and extend laterally therefrom forming a slot for accommodating the free end of the strap, a pair of trunnioiis on said base, one trunnion being on each side of and at the bottom of said base portion, a lever having bearing means on the end thereof journaled on said trunnions, a pair of cooperating jaw members carried by said lever and adapted to grasp the free end of the strap, said lever being pivotable about said trunnions while the free end of the strap is held between said jaws to fold the strap backwardly upon itself while applying a substantially constant tensioning force thereto, and means connected to said jaws and said lever for moving said jaw members as a unit relative to said lever to apply 'tensioning force to the strap.

2. A tool as claimed in claim 1 wherein said base portion comprises a substantially planar bottom Surface, and said trunnions comprise extensions on the outer surfaces of said upstanding flanges.

GASTON CHARLES DELOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 194,226 Doremus Aug. 14, 1877 784,114 Moock Mar. 7, 1905 797,865 Novachesky Aug. 22, 1905 1,474,265 Kenner Nov. 13, 1923 1,505,356 Lindfors Aug. 19, 1924 ,312,400 Govanus Mar. 2, 1943 2,334,637 McKee Nov. 16, 1943 FOREIGN PATENTS Number Country Date 832,522 France July 4, 1938 544,278 Great Britain Apr. 7, 1942 

